The present invention relates to a vehicle exterior component that has a high noise absorbing property. Particularly, the present invention pertains to a vehicle exterior component that covers the outer surface of a wheel housing to absorb noise produced by a wheel and the road surface (pattern noise), thereby preventing the noise from being transmitted to the interior of the vehicle.
Conventionally, nonwoven fabric of polyethylene terephthalate (PET) short fibers is used for guard panels, which are vehicle exterior components. Specifically, such a guard panel includes a fiber web sheet containing a high melting-point PET short fibers and a low melting-point adhesive resin pellets, which are provided in the gaps of the short fibers. The sheet is heated and pressed to melt the pellets and to form a three-dimensional shape. The melted pellets cause the fibers to be adhered to one another. The guard panel is attached to the outer surface of a wheel housing of a vehicle. The guard panel absorbs pattern noise produced by the wheel and the road surface, thereby preventing the noise from being transmitted to the interior of the vehicle.
To facilitate pressing of the guard panel into a desired three-dimensional shape, either relatively large pellets are contained in a fiber web sheet or a great number of small pellets are contained in a fiber web sheet. Therefore, after the pressing, a great number of the gaps of the PET short fibers, which form the unwoven fabric, are occupied by the pellets. This significantly hinders the formation of cells, which are spaces surrounded by the short fibers. Accordingly, the noise absorbing property of the unwove fabric is unsatisfactory.
It is generally known that a greater number of minute cells improve the noise absorbing property of unwoven fabric. However, the cells in the guard panel of the above prior art are excessively large or defectively formed. Further, since the pellets are granulated, the pellets practically cannot convert vibrational energy, which is energy of noise, to frictional energy. The pellets thus do not contribute to the noise absorption.
The present invention was made for solving the above problems in the prior art. Accordingly, it is an objective of the present invention to provide a noise absorbing material and a noise absorbing vehicle exterior component that are easily processed to have three-dimensional shapes, and have high noise absorbing property.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, a vehicle exterior component is provided. The vehicle exterior component includes an unwoven fabric having a noise absorbing function. The unwoven fabric includes main fibers and binder fibers, the melting point of the binder fibers being lower than that of the main fibers. The unwoven fabric further includes a mesh structure in which the main fibers and the binder fibers are intertwined and welded to each other. The mesh structure is obtained by pressing a fiber web in which the main fibers and the binder fibers are intertwined. The unwoven fabric is formed into a predetermined outer shape. The vehicle exterior component also includes at least one additional layer attached to the unwoven fabric. The additional layer has a function other than noise absorbing function.
The present invention may also be applied to a fender liner used in a vehicle that has a tire condition monitoring system. The tire condition monitoring system includes a transmitter for transmitting information of a tire attached to a wheel and a receiver for receiving the transmitted information. The fender liner is located between the transmitter and the receiver. The fender liner includes a base portion made of an unwoven fabric, and a signal passing member located in the base portion. A signal transmitted from the transmitter passes through the signal passing member.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.